Set a rack in the middle of the oven and preheat the oven to 350 degrees. In a mixing bowl, with an electric mixer, slowly beat the almond paste, almond extract, and confectioners' sugar until completely blended. Add the egg white and beat until smooth. Let the batter rest in the refrigerator for 15 minutes. Spoon the batter into a pastry bag fitted with a 1/2-inch tip. Pipe out 1-inch mounds of the batter onto a parchment-lined or nonstick cookie sheet. Bake for 15 to 20 minutes, until puffed and tan. Set on a rack to cool. When completely cool and crisp, chop the macaroons in a food processor. You should have approximately 1 1/4 cups of crumbs.
Tortoni Cream: Spread out almonds on a cookie sheet and place in a preheated 325 degree oven for 3 minutes. Turn tray around, toss nuts with a metal spatula and toast for another 3 minutes. In a large bowl, mix together 1 cup of cream, the macaroon crumbs and confectioners' sugar. Chill for 30 minutes. Mix in the rum and vanilla and chill for another 30 minutes. Whip the remaining 1 cup of cream to soft peaks and fold into the macaroon mixture.
Divide the mixture among eight 4-ounce paper cups. Top with the almonds and cherries, if desired. Freeze for 4 hours or until firm.